Microsoft Office Access: Heap-based buffer overflow enables code execution
Summary
A heap-based buffer overflow in Microsoft Office Access allows an unauthorized attacker to execute code over a network. User interaction is required, for example by opening a crafted file, and attack complexity is high. If exploited, the code runs with the privileges of the user and can affect confidentiality, integrity and availability.
Affected
- Microsoft 365 Apps for Enterprise (the affected version range is not clearly stated in the CNA excerpt; see MSRC)
- Microsoft Office LTSC 2021: 16.0.1 to < 16.0.14334.20974
- Microsoft Office LTSC 2024: 16.0.0 to < 16.0.17932.21056
Fixed in
- Office LTSC 2021: 16.0.14334.20974 (per CNA data via a third-party mirror, not yet verified on MSRC)
- Office LTSC 2024: 16.0.17932.21056 (per CNA data via a third-party mirror, not yet verified on MSRC)
- Microsoft 365 Apps: per-channel builds from third-party mirrors conflict and are unverified; confirm on MSRC
- Update all Office channels to the October 13, 2026 security build
Workaround
Unknown. No vendor workaround was found in the sources reviewed.
Exploitation
- CISA SSVC: exploitation none, automatable no, total technical impact
- Not listed in CISA KEV in a third-party snapshot (not verified against the catalog)
- EPSS 0.00548 (very low predicted exploitation probability, per Rapid7 via Vulners)
- No public proof of concept found; no known in-the-wild exploitation
Our recommendation
- Install the October 2026 security updates for all Microsoft 365 Apps and Office channels.
- Verify the exact fixed builds on the MSRC advisory before the patch deadline.
- Prioritize users who open external database files (.accdb, .mdb) or macro-enabled attachments.
- Keep Protected View enabled and block unsolicited Access files at the mail gateway.
- Monitor for KEV addition or a public proof of concept.
Information from Microsoft (Patch Tuesday October 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-105592 msrc.microsoft.com
- Microsoft 365 Apps security updates learn.microsoft.com
- Vulners MSCVE record: CVE-2026-105592 vulners.com
- Vulners NVD record: CVE-2026-105592 vulners.com
- Rapid7 via Vulners: CVE-2026-105592 vulners.com
- Strix CVE mirror: CVE-2026-105592 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 2 Nov 2026, 19:35.
Original description (NVD)
Heap-based buffer overflow in Microsoft Office Access allows an unauthorized attacker to execute code over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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